Oliver Gear, Inc. (Buffalo, NY), flame-hardens the flanks of large gear teeth to a depth of 0.125 inches on the pitch line without hardening the gear hub.  The gears, weighing from 80 to 3500 pounds with diameters from under 13 inches to almost 55 inches, are used for pinions on reducers.  The flame-hardening system supplied by FTSI consists of two water-quench brass flame heads;  controls for oxygen/fuel rates, flame temperatures and heating times;  a water-cooled heating torch mounted on a scanner mechanism;  a quench collection tank with pumps and turntable;  and a heat exchange assembly.

In operation, gears are locked in place on a free-spinning turntable for flame-hardening.  The hardening process time ranges from one to two minutes per tooth.